More particularly, the invention relates to a vehicle seat comprising:                a seating part,        a backrest mounted so as to pivot on the seating part, for example about at least one axis of rotation,        a hinge mechanism adapted for adjusting the angular position of the backrest relative to the seating part, the hinge mechanism comprising:                    a first frame intended to be fixed to the seating part and a second frame intended to be fixed to the backrest, for example the first frame and the second frame being mounted so as to rotate relative to one another about the axis of rotation,            a blocking device for maintaining the angular position of the second frame relative to the first frame, the blocking device being movable between a blocked position where said release member maintains the angular position of the second frame relative to the first frame and a release position where said blocking device allows the second frame to move relative to the first frame.                        a guide mechanism comprising:                    a track unit comprising a first rail and a second rail both extending in a longitudinal direction and mounted so as to slide relative to one another along the longitudinal direction, in particular the second rail being integrally fixed to the first frame of the hinge mechanism, and            a locking device mounted so as to be movable between a locking position where the position of the second rail relative to the first rail is locked, and an unlocking position where said locking device allows the second rail to move relative to the first rail.                        
Document U.S. Pat. No. 7,374,243B2 discloses an example of a vehicle seat with an actuation device acting on the relative position of a first slide rail relative to a second slide rail and on the relative position of the seating part and backrest in order to fold the seat to provide a larger space for a vehicle occupant to enter the passenger compartment of a vehicle.
In particular, the system described in document U.S. Pat. No. 7,374,243B2 allows fully folding the seating part and backrest against one another before unlocking the seat for translational movement.
The system described in U.S. Pat. No. 7,374,243B2 requires sequencing these two actions to allow easier entry into the passenger compartment of a vehicle. To perform the specific sequence (and avoid translational movement of the seat prior to folding it, which would reduce the desired increase in space for passenger entry), the system described in U.S. Pat. No. 7,374,243B2 comprises a sensor and a control loop to avoid premature translation of the seat before the backrest and seating part are folded down.
The system described in U.S. Pat. No. 7,374,243B2 is therefore complex and cumbersome to implement, with the use of a large control unit, and applies only to the retraction of a motor vehicle seat.
Document US2008/012411 discloses a seat of the aforesaid type which further comprises a single actuation mechanism, adapted to operate selectively in either a backrest control mode, acting on the blocking device to cause movement of the blocking device to the release position, or in a track control mode, acting on the locking device to cause movement of the locking device to the unlocking position, the actuation device being controlled by control means operable by a user to cause the actuation device to operate either in backrest control mode or track control mode.